Transverse and/or commutated flux system stator concepts

ABSTRACT

Disclosed are transverse and/or commutated flux machines and components thereof, and methods of making and using the same. Certain exemplary stators for use in transverse and commutated flux machines may be configured with gaps therebetween, for example in order to counteract tolerance stackup. Other exemplary stators may be configured as partial stators having a limited number of magnets and/or flux concentrators thereon. Partial stators may facilitate ease of assembly and/or use with various rotors. Additionally, exemplary floating stators can allow a transverse and/or commutated flux machine to utilize an air gap independent of the diameter of a rotor. Via use of such exemplary stators, transverse and/or commutated flux machines can achieve improved performance, efficiency, and/or be sized or otherwise configured for various applications.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 12/611,728 filed onNov. 3, 2009 and entitled “TRANSVERSE AND/OR COMMUTATED FLUX SYSTEMSTATOR CONCEPTS”.

U.S. Ser. No. 12/611,728 is a non-provisional of U.S. Provisional No.61/110,874 filed on Nov. 3, 2008 and entitled “ELECTRICAL OUTPUTGENERATING AND DRIVEN ELECTRICAL DEVICES USING COMMUTATED FLUX ANDMETHODS OF MAKING AND USE THEREOF INCLUDING DEVICES WITH TRUNCATEDSTATOR PORTIONS.”

U.S. Ser. No. 12/611,728 is also a non-provisional of U.S. ProvisionalNo. 61/110,879 filed on Nov. 3, 2008 and entitled “ELECTRICAL OUTPUTGENERATING AND DRIVEN ELECTRICAL DEVICES USING COMMUTATED FLUX ANDMETHODS OF MAKING AND USE THEREOF.”

U.S. Ser. No. 12/611,728 is also a non-provisional of U.S. ProvisionalNo. 61/110,884 filed on Nov. 3, 2008 and entitled “METHODS OF MACHININGAND USING AMORPHOUS METALS OR OTHER MAGNETICALLY CONDUCTIVE MATERIALSINCLUDING TAPE WOUND TORROID MATERIAL FOR VARIOUS ELECTROMAGNETICAPPLICATIONS.”

U.S. Ser. No. 12/611,728 is also a non-provisional of U.S. ProvisionalNo. 61/110,889 filed on Nov. 3, 2008 and entitled “MULTI-PHASEELECTRICAL OUTPUT GENERATING AND DRIVEN ELECTRICAL DEVICES WITH TAPEWOUND CORE LAMINATE ROTOR OR STATOR ELEMENTS, AND METHODS OF MAKING ANDUSE THEREOF.”

U.S. Ser. No. 12/611,728 is also a non-provisional of U.S. ProvisionalNo. 61/114,881 filed on Nov. 14, 2008 and entitled “ELECTRICAL OUTPUTGENERATING AND DRIVEN ELECTRICAL DEVICES USING COMMUTATED FLUX ANDMETHODS OF MAKING AND USE THEREOF.”

U.S. Ser. No. 12/611,728 is also a non-provisional of U.S. ProvisionalNo. 61/168,447 filed on Apr. 10, 2009 and entitled “MULTI-PHASEELECTRICAL OUTPUT GENERATING AND DRIVEN ELECTRICAL DEVICES, AND METHODSOF MAKING AND USING THE SAME.” The entire contents of all of theforegoing applications are hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to electrical systems, and in particularto transverse flux machines and commutated flux machines.

BACKGROUND

Motors and alternators are typically designed for high efficiency, highpower density, and low cost. High power density in a motor or alternatormay be achieved by operating at high rotational speed and therefore highelectrical frequency. However, many applications require lowerrotational speeds. A common solution to this is to use a gear reduction.Gear reduction reduces efficiency, adds complexity, adds weight, andadds space requirements. Additionally, gear reduction increases systemcosts and increases mechanical failure rates.

Additionally, if a high rotational speed is not desired, and gearreduction is undesirable, then a motor or alternator typically must havea large number of poles to provide a higher electrical frequency at alower rotational speed. However, there is often a practical limit to thenumber of poles a particular motor or alternator can have, for exampledue to space limitations. Once the practical limit is reached, in orderto achieve a desired power level the motor or alternator must berelatively large, and thus have a corresponding lower power density.

Moreover, existing multipole windings for alternators and electricmotors typically require winding geometry and often complex windingmachines in order to meet size and/or power needs. As the number ofpoles increases, the winding problem is typically made worse.Additionally, as pole count increases, coil losses also increase (forexample, due to resistive effects in the copper wire or other materialcomprising the coil). However, greater numbers of poles have certainadvantages, for example allowing a higher voltage constant per turn,providing higher torque density, and producing voltage at a higherfrequency.

Most commonly, electric motors are of a radial flux type. To a farlesser extent, some electric motors are implemented as transverse fluxmachines and/or commutated flux machines. It is desirable to developimproved electric motor and/or alternator performance and/orconfigurability. In particular, improved transverse flux machines and/orcommutated flux machines are desirable.

SUMMARY

This disclosure relates to transverse and/or commutated flux machines.In an exemplary embodiment, an electrical machine comprises a rotor, anda partial stator assembly. The partial stator assembly comprises a fluxconcentrator, a first magnet connected to a first side of the fluxconcentrator, and a second magnet connected to a second side of the fluxconcentrator opposite the first side. The first magnet and the secondmagnet are magnetically oriented such that a common magnetic pole ispresent on the first and second sides of the flux concentrator. Theelectrical machine further comprises a guide mechanism configured toachieve a specified air gap between the rotor and the partial statorassembly. The electrical machine is at least one of a transverse fluxmachine or a commutated flux machine.

In another exemplary embodiment, a method of configuring an electricalmachine comprises coupling a truncated stator to a rotor via a guidemechanism, the rotor having a diameter, and configuring the guidemechanism to achieve a desired air gap between the truncated stator andthe rotor. The desired air gap is independent of the diameter of therotor, and the electrical machine is at least one of a transverse fluxmachine or a commutated flux machine.

The contents of this summary section are provided only as a simplifiedintroduction to the disclosure, and are not intended to be used to limitthe scope of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the following description, appended claims, andaccompanying drawings:

FIG. 1A illustrates an exemplary transverse flux machine in accordancewith an exemplary embodiment;

FIG. 1B illustrates an exemplary commutated flux machine in accordancewith an exemplary embodiment;

FIG. 2A illustrates an exemplary axial gap configuration in accordancewith an exemplary embodiment;

FIG. 2B illustrates an exemplary radial gap configuration in accordancewith an exemplary embodiment;

FIG. 3A illustrates an exemplary cavity engaged configuration inaccordance with an exemplary embodiment;

FIG. 3B illustrates an exemplary face engaged configuration inaccordance with an exemplary embodiment;

FIG. 3C illustrates an exemplary face engaged axial gap configuration inaccordance with an exemplary embodiment;

FIG. 4 illustrates various motor performance curves in accordance withan exemplary embodiment;

FIG. 5 illustrates, in a cut-away view, an exemplary transverse fluxmachine configured for use in a vehicle in accordance with an exemplaryembodiment;

FIG. 6 illustrates a side perspective view of an exemplary commutatedflux machine section in accordance with an exemplary embodiment;

FIG. 7 illustrates a perspective view of an exemplary gapped statorcoupled with an exemplary rotor and coil in accordance with an exemplaryembodiment;

FIGS. 8A-8C illustrate exemplary partial stators coupled to a rotor inaccordance with an exemplary embodiment;

FIGS. 9A-9C illustrate exemplary partial stators and truncated coilscoupled to an exemplary electronics board in accordance with anexemplary embodiment; and

FIGS. 10A-10B illustrate an exemplary floating stator in accordance withan exemplary embodiment.

DETAILED DESCRIPTION

While exemplary embodiments are described herein in sufficient detail toenable those skilled in the art to practice the invention, it should beunderstood that other embodiments may be realized and that logicalelectrical, magnetic, and/or mechanical changes may be made withoutdeparting from the spirit and scope of the present disclosure. Thus, thefollowing descriptions are not intended as a limitation on the use orapplicability of the present disclosure, but instead, are providedmerely to enable a full and complete description of exemplaryembodiments.

For the sake of brevity, conventional techniques for electrical systemconstruction, management, operation, measurement, optimization, and/orcontrol, as well as conventional techniques for magnetic fluxutilization, concentration, control, and/or management, may not bedescribed in detail herein. Furthermore, the connecting lines shown invarious figures contained herein are intended to represent exemplaryfunctional relationships and/or physical couplings between variouselements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical electrical system, for example an AC synchronous electricmotor.

Prior electric motors, for example conventional DC brushless motors,suffer from various deficiencies. For example, many electric motors areinefficient at various rotational speeds and/or loads, for example lowrotational speeds. Thus, the motor is typically operated within a narrowRPM range and/or load range of suitable efficiency. In theseconfigurations, gears or other mechanical approaches may be required inorder to obtain useful work from the motor.

Moreover, many electric motors have a low pole count. Because power is afunction of torque and RPM, such motors must often be operated at a highphysical RPM in order to achieve a desired power density and/orelectrical frequency. Moreover, a higher power density (for example, ahigher kilowatt output per kilogram of active electrical and magneticmotor mass) optionally is achieved by operating the motor at highrotational speed and therefore high electrical frequency. However, highelectrical frequency can result in high core losses and hence lowerefficiency. Moreover, high electrical frequency can result in increasedcost, increased mechanical complexity, and/or decreased reliability.Additionally, high electrical frequency and associated losses createheat that may require active cooling, and can limit the operationalrange of the motor. Heat can also degrade the life and reliability of ahigh frequency machine.

Still other electric motors contain large volumes of copper wire orother coil material. Due to the length of the coil windings, resistiveeffects in the coil lead to coil losses. For example, such lossesconvert a portion of electrical energy into heat, reducing efficiencyand potentially leading to thermal damage to and/or functionaldestruction of the motor.

Moreover, many prior electric motors offered low torque densities. Asused herein, “torque density” refers to Newton-meters produced perkilogram of active electrical and magnetic materials. For example, manyprior electric motors are configured with a torque density from about0.5 Newton-meters per kilogram to about 3 Newton-meters per kilogram.Thus, a certain electric motor with a torque density of 1 Newton-meterper kilogram providing, for example, 10 total Newton-meters of torquemay be quite heavy, for example in excess of 10 kilograms of activeelectrical and magnetic materials. Similarly, another electric motorwith a torque density of 2 Newton-meters per kilogram providing, forexample, 100 total Newton-meters of torque may also be quite heavy, forexample in excess of 50 kilograms of active electrical and magneticmaterials. As can be appreciated, the total weight of these electricmotors, for example including weight of frame components, housings, andthe like, may be significantly higher. Moreover, such prior electricmotors are often quite bulky as a result of the large motor mass. Often,a motor of sufficient torque and/or power for a particular applicationis difficult or even impossible to fit in the available area.

Even prior transverse flux machines have been unable to overcome thesedifficulties. For example, prior transverse flux machines have sufferedfrom significant flux leakage. Still others have offered torquedensities of only a few Newton-meters per kilogram of active electricaland magnetic materials. Moreover, various prior transverse flux machineshave been efficiently operable only within a comparatively narrow RPMand/or load range. Additionally, using prior transverse flux machines togenerate substantial output power often required spinning relativelymassive and complicated components (i.e., those involving permanentmagnets and/or relatively exotic, dense and/or expensive fluxconcentrating or conducting materials) at high rates of speed. Suchhigh-speed operation requires additional expensive and/or complicatedcomponents for support and/or system reliability. Moreover, many priortransverse flux machines are comparatively expensive and/or difficult tomanufacture, limiting their viability.

In contrast, various of these problems can be solved by utilizingtransverse flux machines configured in accordance with principles of thepresent disclosure. As used herein, a “transverse flux machine” and/or“commutated flux machine” may be any electrical machine wherein magneticflux paths have sections where the flux is generally transverse to arotational plane of the machine. In an exemplary embodiment, when amagnet and/or flux concentrating components are on a rotor and/or aremoved as the machine operates, the electrical machine may be a pure“transverse” flux machine. In another exemplary embodiment, when amagnet and/or flux concentrating components are on a stator and/or areheld stationary as the machine operates, the electrical machine may be apure “commutated” flux machine. As is readily apparent, in certainconfigurations a “transverse flux machine” may be considered to be a“commutated flux machine” by fixing the rotor and moving the stator, andvice versa. Moreover, a coil may be fixed to a stator; alternatively, acoil may be fixed to a rotor.

Moreover, there is a spectrum of functionality and device designsbridging the gap between a commutated flux machine and a transverse fluxmachine. Certain designs may rightly fall between these two categories,or be considered to belong to both simultaneously. Therefore, as will beapparent to one skilled in the art, in this disclosure a reference to a“transverse flux machine” may be equally applicable to a “commutatedflux machine” and vice versa.

Moreover, transverse flux machines and/or commutated flux machines maybe configured in multiple ways. For example, with reference to FIG. 2A,a commutated flux machine may be configured with a stator 210 generallyaligned with the rotational plane of a rotor 250. Such a configurationis referred to herein as “axial gap.” In another configuration, withreference to FIG. 2B, a commutated flux machine may be configured withstator 210 rotated about 90 degrees with respect to the rotational planeof rotor 250. Such a configuration is referred to herein as “radialgap.”

With reference now to FIG. 3A, a flux switch 352 in a commutated fluxmachine may engage a stator 310 by extending at least partially into acavity defined by stator 310. Such a configuration is referred to hereinas “cavity engaged.” Turning to FIG. 3B, flux switch 352 in a commutatedflux machine may engage stator 310 by closely approaching two terminalfaces of stator 310. Such a configuration is referred to herein as “faceengaged.” Similar engagement approaches may be followed in transverseflux machines and are referred to in a similar manner.

In general, a transverse flux machine and/or commutated flux machinecomprises a rotor, a stator, and a coil. A flux switch may be located onthe stator or the rotor. As used herein, a “flux switch” may be anycomponent, mechanism, or device configured to open and/or close amagnetic circuit. (i.e., a portion where the permeability issignificantly higher than air). A magnet may be located on the stator orthe rotor. A coil is at least partially enclosed by the stator or therotor. Optionally, flux concentrating portions may be included on thestator and/or the rotor. With momentary reference now to FIG. 1A, anexemplary transverse flux machine 100A may comprise a rotor 150A, astator 110A, and a coil 120A. In this exemplary embodiment, a magnet maybe located on rotor 150A. With momentary reference now to FIG. 1B, anexemplary commutated flux machine 100B may comprise a rotor 150B, astator 110B, and a coil 120B. In this exemplary embodiment, a magnet maybe located on stator 110B.

Moreover, a transverse flux machine and/or commutated flux machine maybe configured with any suitable components, structures, and/or elementsin order to provide desired electrical, magnetic, and/or physicalproperties. For example, a commutated flux machine having a continuous,thermally stable torque density in excess of 50 Newton-meters perkilogram may be achieved by utilizing a polyphase configuration. As usedherein, “continuous, thermally stable torque density” refers to a torquedensity maintainable by a motor, without active cooling, duringcontinuous operation over a period of one hour or more. Moreover, ingeneral, a continuous, thermally stable torque density may be consideredto be a torque density maintainable by a motor for an extended durationof continuous operation, for example one hour or more, without thermalperformance degradation and/or damage.

Moreover, a transverse flux machine and/or commutated flux machine maybe configured to achieve low core losses. By utilizing materials havinghigh magnetic permeability, low coercivity, low hysteresis losses, loweddy current losses, and/or high electrical resistance, core losses maybe reduced. For example, silicon steel, powdered metals, plated powderedmetals, soft magnetic composites, amorphous metals, nanocrystallinecomposites, and/or the like may be utilized in rotors, stators,switches, and/or other flux conducting components of a transverse fluxmachine and/or commutated flux machine. Eddy currents, flux leakage, andother undesirable properties may thus be reduced.

A transverse flux machine and/or commutated flux machine may also beconfigured to achieve low core losses by varying the level of saturationin a flux conductor, such as in an alternating manner. For example, aflux conducting element in a stator may be configured such that a firstportion of the flux conducting element saturates at a first time duringoperation of the stator. Similarly, a second portion of the same fluxconducting element saturates at a second time during operation of thestator. In this manner, portions of the flux conducting element have alevel of magnetic flux density significantly below the saturationinduction from time to time, reducing core loss. For example,significant portions of the flux conducting element may have a level offlux density less than 25% of the saturation induction within the 50% ofthe time of its magnetic cycle. Moreover, any suitable flux densityvariations may be utilized.

Furthermore, a transverse flux machine and/or commutated flux machinemay be configured to achieve low coil losses. For example, in contrastto a conventional electric motor utilizing a mass of copper C in one ormore coils in order to achieve a desired output power P, a particulartransverse flux machine and/or commutated flux machine may utilize onlya small amount of copper C (for example, one-tenth as much copper C)while achieving the same output power P. Additionally, a transverse fluxmachine and/or commutated flux machine may be configured to utilize coilmaterial in an improved manner (for example, by reducing and/oreliminating “end turns” in the coil). In this manner, resistive losses,eddy current losses, thermal losses, and/or other coil losses associatedwith a given coil mass C may be reduced. Moreover, within a transverseflux machine and/or commutated flux machine, a coil may be configured,shaped, oriented, aligned, manufactured, and/or otherwise configured tofurther reduce losses for a given coil mass C.

Additionally, in accordance with principles of the present disclosure, atransverse flux machine and/or commutated flux machine may be configuredto achieve a higher voltage constant. In this manner, the number ofturns in the machine may be reduced, in connection with a higherfrequency. A corresponding reduction in coil mass and/or the number ofturns in the coil may thus be achieved.

Yet further, in accordance with principles of the present disclosure, atransverse flux machine and/or commutated flux machine may be configuredto achieve a high flux switching frequency, for example a flux switchingfrequency in excess of 1000 Hz. Because flux is switched at a highfrequency, torque density may be increased.

With reference now to FIG. 4, a typical conventional electric motorefficiency curve 402 for a particular torque is illustrated. Revolutionsper minute (RPM) is illustrated on the X axis, and motor efficiency isillustrated on the Y axis. As illustrated, a conventional electric motortypically operates at a comparatively low efficiency at low RPM. Forthis conventional motor, efficiency increases and then peaks at aparticular RPM, and eventually falls off as RPM increases further. As aresult, many conventional electric motors are often desirably operatedwithin an RPM range near peak efficiency. For example, one particularprior art electric motor may have a maximum efficiency of about 90% atabout 3000 RPM, but the efficiency falls off dramatically at RPMs thatare not much higher or lower.

Gearboxes, transmissions, and other mechanical mechanisms are oftencoupled to an electric motor to achieve a desired output RPM or otheroutput condition. However, such mechanical components are often costly,bulky, heavy, and/or impose additional energy losses, for examplefrictional losses. Such mechanical components can reduce the overallefficiency of the motor/transmission system. For example, an electricmotor operating at about 90% efficiency coupled to a gearbox operatingat about 70% efficiency results in a motor/gearbox system having anoverall efficiency of about 63%. Moreover, a gearbox may be largerand/or weigh more or cost more than the conventional electric motoritself. Gearboxes also reduce the overall reliability of the system.

In contrast, with continuing reference to FIG. 4 and in accordance withprinciples of the present disclosure, a transverse and/or commutatedflux machine efficiency curve 404 for a particular torque isillustrated. In accordance with principles of the present disclosure, atransverse and/or commutated flux machine may rapidly reach a desirableefficiency level (for example, 80% efficiency or higher) at an RPM lowerthan that of a conventional electric motor. Moreover, the transverseand/or commutated flux machine may maintain a desirable efficiency levelacross a larger RPM range than that of a conventional electric motor.Additionally, the efficiency of the transverse and/or commutated fluxmachine may fall off more slowly past peak efficiency RPM as compared toa conventional electric motor.

Furthermore, in accordance with principles of the present disclosure, atransverse and/or commutated flux machine may achieve a torque densityhigher than that of a conventional electric motor. For example, in anexemplary embodiment a transverse and/or commutated flux machine mayachieve a continuous, thermally stable torque density in excess of 100Newton-meters per kilogram.

Thus, in accordance with principles of the present disclosure, atransverse and/or commutated flux machine may desirably be employed invarious applications. For example, in an automotive application, atransverse and/or commutated flux machine may be utilized as a wheel hubmotor, as a direct driveline motor, and/or the like. Moreover, in anexemplary embodiment having a sufficiently wide operational RPM range,particularly at lower RPMs, a transverse and/or commutated flux machinemay be utilized in an automotive application without need for atransmission, gearbox, and/or similar mechanical components.

An exemplary electric or hybrid vehicle embodiment comprises atransverse flux motor for driving a wheel of the vehicle, wherein thevehicle does not comprise a transmission, gearbox, and/or similarmechanical component(s). In this exemplary embodiment, the electric orhybrid vehicle is significantly lighter than a similar vehicle thatcomprises a transmission-like mechanical component. The reduced weightmay facilitate an extended driving range as compared to a similarvehicle with a transmission like mechanical component. Alternatively,weight saved by elimination of the gearbox allows for utilization ofadditional batteries for extended range. Moreover, weight saved byelimination of the gearbox allows for additional structural material forimproved occupant safety. In general, a commutated flux machine having abroad RPM range of suitable efficiency may desirably be utilized in avariety of applications where a direct-drive configuration isadvantageous. For example, a commutated flux machine having anefficiency greater than 80% over an RPM range from only a few RPMs toabout 2000 RPMs may be desirably employed in an automobile.

Moreover, the exemplary transmissionless electric or hybrid vehicle mayhave a higher overall efficiency. Stated otherwise, the exemplaryvehicle may more efficiently utilize the power available in thebatteries due to the improved efficiency resulting from the absence of atransmission-like component between the motor and the wheel of thevehicle. This, too, is configured to extend driving range and/or reducethe need for batteries.

Additionally, the commutated flux machine is configured to have a hightorque density. In accordance with principles of the present disclosure,the high torque density commutated flux machine is also well suited foruse in various applications, for example automotive applications. Forexample, a conventional electric motor may have a torque density ofbetween about 0.5 to about 3 Newton-meters per kilogram. Additionaltechniques, for example active cooling, can enable a conventionalelectric motor to achieve a torque density of up to about 50Newton-meters per kilogram. However, such techniques typically addsignificant additional system mass, complexity, bulk, and/or cost.Additionally, such conventional electric motors configured to producecomparatively high amounts of torque, for example the Siemens 1FW6motor, are limited to comparatively low RPM operation, for exampleoperation below 250 RPMs.

In contrast, in accordance with principles of the present disclosure, anexemplary passively cooled transverse flux machine and/or commutatedflux machine may be configured with a continuous, thermally stabletorque density in excess of 50 Newton-meters per kilogram. As usedherein, “passively cooled” is generally understood to refer to systemswithout cooling components requiring power for operation, for examplewater pumps, oil pumps, cooling fans, and/or the like. Moreover, thisexemplary transverse flux machine and/or commutated flux machine may beconfigured with a compact diameter, for example a diameter less than 14inches. Another exemplary transverse flux machine and/or commutated fluxmachine may be configured with a continuous, thermally stable torquedensity in excess of 100 Newton-meters per kilogram and a diameter lessthan 20 inches. Accordingly, by utilizing various principles of thepresent disclosure, exemplary transverse flux machines and/or commutatedflux machines may be sized and/or otherwise configured and/or shaped ina manner suitable for mounting as a wheel hub motor in an electricvehicle, because the transverse flux machine and/or commutated fluxmachine is significantly lighter and/or more compact than a conventionalelectric motor. In this manner, the unsprung weight of the resultingwheel/motor assembly can be reduced. This can improve vehicle handlingand reduce the complexity and/or size of suspension components.

Further, in accordance with principles of the present disclosure, atransverse flux machine and/or commutated flux machine may desirably beutilized in an electromechanical system having a rotating portion, forexample a washing machine or other appliance. In one example, aconventional washing machine typically utilizes an electric motorcoupled to a belt drive to spin the washer drum. In contrast, atransverse flux machine and/or commutated flux machine may be axiallycoupled to the washer drum, providing a direct drive configuration andeliminating the belt drive element. Alternatively, a transverse fluxmachine and/or commutated flux machine, for example one comprising apartial stator, may be coupled to a rotor. The rotor may have a commonaxis as the washer drum. The rotor may also be coupled directly to thewasher drum and/or integrally formed therefrom. In this manner, atransverse flux machine and/or commutated flux machine may providerotational force for a washing machine or other similarelectromechanical structures and/or systems.

Moreover, in accordance with principles of the present disclosure, atransverse flux machine and/or commutated flux machine may desirably beutilized to provide mechanical output to relatively lightweight vehiclessuch as bicycles, scooters, motorcycles, quads, golf carts, or othervehicles. Additionally, a transverse flux machine and/or commutated fluxmachine may desirably be utilized in small engine applications, forexample portable generators, power tools, and other electricalequipment. A transverse flux machine and/or commutated flux machine maydesirably be utilized to provide mechanical output to propeller-drivendevices, for example boats, airplanes, and/or the like. A transverseflux machine and/or commutated flux machine may also desirably beutilized in various machine tools, for example rotating spindles, tablesconfigured to move large masses, and/or the like. In general, transverseflux machines and/or commutated flux machines may be utilized to provideelectrical and/or mechanical input and/or output to and/or from anysuitable devices.

An electrical system, for example an electric motor, may be any systemconfigured to facilitate the switching of magnetic flux. In accordancewith an exemplary embodiment and with reference again to FIG. 1A, anelectrical system, for example transverse flux machine 100A, generallycomprises a rotor portion 150A, a stator portion 110A, and a coil 120A.Rotor portion 150A is configured to interact with stator portion 110A inorder to facilitate switching of magnetic flux. Stator portion 110A isconfigured to be magnetically coupled to rotor portion 150A, and isconfigured to facilitate flow of magnetic flux via interaction withrotor portion 150A. Coil 120A is configured to generate an outputresponsive to flux switching and/or accept a current input configured todrive the rotor. Transverse flux machine 100A may also comprise variousstructural components, for example components configured to facilitateoperation of transverse flux machine 100A. Moreover, transverse fluxmachine 100A may comprise any suitable components configured to support,guide, modify, and/or otherwise manage and/or control operation oftransverse flux machine 100A and/or components thereof.

In accordance with an exemplary embodiment and with renewed reference toFIG. 1B, a commutated flux machine (CFM) system 100B comprises a stator110 (for example, stator 110B), a rotor 150 (for example, rotor 150B),and a coil 120 (for example, coil 120B). In various embodiments, CFMsystem 100B has a generally circumferential stator which comprisesmultiple magnets 111B and flux concentrators 112B to form a completecircle. In an exemplary embodiment, stator 110B partially encloses coil120B. Furthermore, rotor 150B has passive switching elements 151B, androtates to interact with stator 110B and switch magnetic flux.

In an exemplary embodiment of the circumferential stator 110B, magnets111B and flux concentrators 112B are arranged in alternating fashion. Inone exemplary embodiment, magnets 111B are magnetically oriented inalternating directions while interleaving with flux concentrators 112B.Stated another way, magnets 111B may be arranged so that a northmagnetic side of a particular magnet 111B is facing a north magneticside of another magnet 111B, with a flux concentrator 112B therebetween.Likewise, a south magnetic side may be oriented facing another southmagnetic side, separated by a flux concentrator 112B. The interleavingand alternating directions result in each flux concentrator 112B havinga net magnetic pole.

In an exemplary embodiment, and with reference now to FIG. 5, atransverse and/or commutated flux machine may be implemented withmultiple partial stators, for example as a wheel hub motor. For example,a transverse flux machine 500 may comprise a rotor 550, one or morecoils 520 (shown as 520A and 520B), and one or more partial stators 510(shown as 510A, 510B, and 510C). Moreover, via use of a plurality ofpartial stators, transverse flux machine 500 may be configured toproduce polyphase output and/or operate responsive to polyphase input,for example when each of the plurality of partial stators correspond toa different phase.

With reference now to FIG. 6, in an exemplary embodiment a CFM statorunit 610 comprises a flux concentrator 612 and a magnet 611 that areboth substantially C-shaped. The C-shaped components 611, 612 can bedefined as having a first leg 615, a second leg 616, and a returnportion 617 that connects to the first and second legs 615, 616. In anexemplary embodiment, CFM stator unit 610 is generally C-shaped toaccommodate a substantially annular or doughnut shaped rotor portion 650in a cavity engaged configuration. In another exemplary embodiment, CFMstator unit 610 is configured to be face engaged with rotor portion 650.Furthermore, in addition to C-shaped, in exemplary embodiments theshapes of the stator components may be U-shaped, rectangular,triangular, rounded cross-sectional shapes, and/or any other suitableshapes known to one skilled in the art.

In an exemplary embodiment, a stator further comprises a structuralsupport that holds the magnets and flux concentrators for assemblyand/or spacing. The structural support is designed to not interfere withthe motion of the CFM system. In another exemplary embodiment, thestator further comprises cooling devices. The cooling devices mayinclude radiative portions, conductive cooling portions, and/or thelike. In yet another exemplary embodiment, the stator may also comprisecomponents that measure certain characteristics of the device, such asHall effect sensors and/or the like. Furthermore, in various exemplaryembodiments the stator comprises components configured to drive therotor.

With reference again to FIG. 6, CFM stator unit 610 may at leastpartially enclose a coil 620. Coil 620 may be any suitable height,width, and/or length to generate an electrical current responsive toflux switching in the stator. Coil 620 may also be any suitable height,width, and/or length configured to transfer a current to drive therotor. In an embodiment, coil 620 is circular about an axis of rotation.In various exemplary embodiments, coil 620 has a diameter of betweenapproximately 2 inches and approximately 36 inches in the plane ofrotation. Moreover, coil 620 may have any suitable diameter, length,and/or other dimensions and/or geometries, as desired.

In an exemplary embodiment, coil 620 is coupled to an interior surfaceof concentrator 611. Moreover, in another exemplary embodiment,concentrator 611 is “wrapped” around coil 620 so that the interiorsurface of concentrator 611 is slightly larger than the height and widthof coil 620 with as little as gap as possible. Coil 620 may also bedesirably spaced away from and/or magnetically insulated from rotorswitch 650, for example in order to reduce eddy currents and/or otherinduced effects in coil 620 responsive to flux switching near thesurface of rotor switch 650.

In an exemplary embodiment, coil 620 is electrically coupled to acurrent source. The current source may be any suitable current source,but in one exemplary embodiment the current source is alternating power.It should be noted that coil 620 could be connected to be a source ingeneral applications.

In an exemplary embodiment, coil 620 is generally constructed fromcopper. However, coil 620 may be made out of any suitable electricallyconductive material and/or materials such as copper, silver, gold,aluminum, superconducting materials, and/or the like. In an exemplaryembodiment, coil 620 is a loop. The loop is in contrast to windings,which may have greater losses than a single loop. Furthermore, coil 620may be one solid piece, or may be made by coiling, layering, stacking,and/or otherwise joining many smaller strands or wires of electricallyconductive material and/or low-loss materials together.

In accordance with an exemplary embodiment, the stator and rotorinteract to create a magnetic flux circuit. Flux conduction is created,for example, by the switching elements of the rotor bridging the gapbetween opposite pole flux concentrators. In an exemplary embodiment,opposite pole flux concentrators are adjacent in the stator. In variousexemplary embodiments, a flux path is created through the switchingelements of the rotor. In another exemplary embodiment, a flux path iscreated through a magnet separating the adjacent flux concentrators. Inan exemplary embodiment, AC synchronous flux flow is generated inresponse to similar flux conduction and flux paths being createdsimultaneously in adjacent flux concentrators. In another exemplaryembodiment, asynchronous flux flow is generated in response to fluxconduction and flux paths being created in adjacent flux concentratorsat slightly delayed intervals.

In an exemplary generator embodiment, as the rotor moves into newposition relative to the stator, flux flows in an opposite directionwithin the stator as compared to a prior position of the rotor. Thechange in flux direction causes the flux to be conducted around the coilin alternating directions. The alternating flux direction results ingeneration of alternating electrical output in the coil.

In an exemplary motor embodiment, the rotor is driven to rotate. Therotor movement is controlled, in an exemplary embodiment, by a controlsystem which controls, for example, rotor RPM, axial positioning,acceleration, rotational direction, deceleration, starting, and/orstopping. In an exemplary embodiment, the rotor is driven in eitherdirection (clockwise or counterclockwise), for example depending on apreference of an operator. The control system may further compriseprogramming memory, and a user interface, which may include graphics.The control system may include ports for coupling to additionalelectrical devices and/or may be coupled to additional electricaldevices wirelessly. The control system may further comprise sensors formonitoring and measuring desired values of the system. These values mayinclude one or more of phase matching, phase propagation, outputwaveforms, flux density, voltage constant, torque constant, webers offlux switched, RPM, system malfunctions, and/or the like. A power sourcemay be coupled to the control system. This power source may be anysuitable power source for operation of the control system, such asalternating current, direct current, capacitive charge, and/orinductance. In an exemplary embodiment, the power source is a DCbattery.

Portions of rotor and/or stator elements may comprise any suitable fluxconducting material and/or materials, such as steel, silicon steel,amorphous metals, metallic glass alloys, nanocrystaline composite, andpowdered metals such as powdered iron.

In an exemplary embodiment, portions of a commutated and/or transverseflux machine, for example CFM system 100B, such as portions of thestator 110B or rotor 150B may be comprised of Metglas® brand amorphousmetal products produced by Hitachi Metals America, for example Metglas®brand magnetic alloy 2605SA1 and/or the like. In general, such magneticalloys have excellent flux conducing properties (e.g., permeability, forexample, may be up to hundreds of thousands of times the permeability ofsilicon steel). Such magnetic alloys are also resistant to the effectsof heat and losses), such as may occur with high speed operation ofdevices in accordance with aspects of the present disclosure. Forexample, losses for devices using such magnetic alloys, compared tousing silicon steel, may be reduced from about 800 watts to about 30watts or less, in some exemplary applications. Moreover, utilization ofsuch magnetic alloys can allow for higher speed operation without theneed for auxiliary cooling. For example, a device using magnetic alloyin place of silicon steel may be configured to achieve a continuousoperation at a higher RPM, for example an RPM two times greater, fivetimes greater, ten times greater, or even more. These features, inaddition to other factors, allow the power to weight ratios of exemplarytransverse and/or commutated flux devices to increase.

In certain exemplary embodiments, portions of CFM system 100B, such asportions of stator 110B or rotor 150B, may be comprised of stackedlaminated steel. The orientation of the laminations may be varied toenhance flux transmission. For instance, certain laminations may beoriented in a radial direction. This approach may enhance mechanicalstrength and/or ease assembly. Alternatively, such as for a returnportion in a flux conducting element of a stator, the surfaces of thelaminations may be oriented parallel to the direction of fluxtransmission, thereby reducing eddy currents and/or other losses.Minimizing eddy current effects and/or otherwise enhancing fluxtransmission can be achieved using powdered iron; however, powdered irongenerally does not conduct magnetic flux as efficiently as, for example,steel laminate (or other flux conducting material, such as Metglas®2605SA1) and does not include the physical layer features potentiallyuseful in minimizing or otherwise addressing eddy current and otherlosses. In addition, the use of powdered iron has the further drawbackof increased hysteresis losses.

In an exemplary embodiment, portions of CFM system 100B, such asportions of the stator magnets, may comprise rare earth permanentmagnets. Magnetic material may comprise any suitable material, forexample neodymium-iron-boron (NIB) material. In an exemplary embodiment,the rare earth permanent magnets have a suitable magnetic field, forexample a field in the range of 0.5 to 2.5 Tesla. In other exemplaryembodiments, the stator magnets comprise inducted magnets and/orelectromagnets. The inducted magnets and/or electromagnets may be madeout of iron, iron alloys, metallic alloys, and/or the like, as well asother suitable materials as is known.

In an exemplary embodiment, a flux concentrator gathers the flux fromone or more coupled magnets. A flux concentrator is typically made ofsome form of iron, such as silicon steel, powdered metals, amorphousmetals, metallic glass alloys, nanocrystalline composite, and/or thelike. Furthermore, in various exemplary embodiments, the fluxconcentrator may be made out of any suitable material, for example amaterial with a high permeability, high flux saturation, and/or highelectrical resistance.

In addition to a circumferential CFM system as described, various otherconfigurations of a CFM stator may be utilized. These otherconfigurations include, but are not limited to, a gapped stator, apartial stator, and a floating stator.

In an exemplary embodiment and with reference now to FIG. 7, a gappedstator CFM system 700 comprises multiple commutated flux stator sections701 assembled generally about the circumference of a coil 720 and arotor 750. The gapped stator CRM system 700 further comprises a gap 702between each of the multiple commutated flux stator sections 701.Furthermore, in an exemplary embodiment, a structural support (notshown) is located in gap 702 of gapped stator system 700.

In accordance with an exemplary embodiment, gapped stator CFM system 700further comprises a support structure. The support structure holdsmultiple commutated flux stator sections 701 into place. In an exemplaryembodiment, the support structure comprises several sections configuredto hold the magnets and flux concentrators. Commutated flux statorsections 701 may be partitioned using spacers, for example portions ofthe support structure. The spacers may be configured to provide properalignment of the multiple commutated flux stator sections 701. In anexemplary embodiment, the spacers are approximately as thick as a magnetin commutated flux stator sections 701. Moreover, the spacers may haveany suitable thickness, as desired.

In various exemplary embodiments, the number of commutated flux statorsections 701 in gapped stator system 700 may range from 2 to 360 ormore. The arc length of the multiple commutated flux stator sections 701is less than the circumference of rotor 750. As defined herein, the arclength of multiple commutated flux stator sections 701 is theencompassed distance of rotor 750, not including the gap distance. Invarious exemplary embodiments, the total arc length of multiplecommutated flux stator sections 701 is in the range of about 1% to about95% of the circumference of rotor 750. In one embodiment, multiplecommutated flux stator sections 701 are equally distributed about rotor750 to form a substantially circumferential stator. In anotherembodiment, multiple commutated flux stator sections 701 are unequallydistributed about rotor 750. For example, multiple commutated fluxstator sections 701 may be located on only half of the circumference ofrotor 750.

In another example, multiple commutated flux stator sections 701 areconfigured with uneven distances between each section. However, in an ACsynchronous embodiment, multiple commutated flux stator sections 701 aretypically located such that the switching portions of rotor 750 canmagnetically engage each of multiple commutated flux stator sections701. This can be accomplished, for example, by designing the distancebetween multiple commutated flux stator sections 701 to be a multiple ofthe distance between the switching elements of rotor 750.

In an exemplary embodiment, first magnet 711 has an outer edge parallelto, and opposite of, the interface between first magnet 711 and fluxconcentrator 712. Similarly, in the exemplary embodiment, second magnet713 has an outer edge parallel to, and opposite of, the interfacebetween second magnet 713 and flux concentrator 712. Stated another way,commutated flux stator section 701, in one embodiment, is “square” withrespect to coil 720. In an exemplary embodiment, a “square” commutatedflux stator section 701 facilitates manufacturing and assembly. In amodular approach, each commutated flux stator section 701 ismanufactured with substantially flush inner cavities instead of roundedinner cavities. However, magnets 711, 713 and/or flux concentrator 712can also be angled. For example, magnets 711, 713 might have a narrowfirst leg in comparison to the second leg, creating a tapered shape.Furthermore, flux concentrator 712 can also be tapered towards the axisof rotation of rotor 750. Moreover, magnets 711, 712 and/or fluxconcentrators 712 may be shaped, sized, and/or otherwise configured inany suitable manner, for example to achieve a desired torque density,output voltage waveform, and/or the like.

An advantage of a gapped stator configuration compared to a similarcircumferential stator configuration is a decrease in weight. Anotheradvantage is a decrease in the amount of magnetic material. Lessmagnetic material can result in a less expensive system. A decrease isweight is an advantage in various applications where a lower power issufficient but extra weight is undesirable, for example due tostructural stress.

In an exemplary embodiment, gaps 702 between commutated flux statorsections 701 are configured to provide ventilation for cooling. In otherexemplary embodiments, various heat extraction devices such as heatsinks, other heat dispersive materials, fan blades, and/or othersuitable devices may be added to and/or placed at least partially withingaps 702 between commutated flux stator sections 701.

Furthermore, in addition to cooling devices, other devices may belocated in gaps 702 between commutated flux stator sections 701. In anexemplary embodiment, one or more measuring devices are located in gaps702. The measuring devices, for example, may include devices to measureRPM, magnetic field strength, efficiency of the system, and/or the like.

Another advantage of gapped stator CFM system 700 is generally directedto assembly and/or repair of the stator. In an exemplary embodiment,commutated flux stator sections 701 are modular. Moreover, sections 701may be separately removable and/or removable in multiple groups. Such amodular approach to assembly and/or disassembly results in easierreplacement, as the removal and replacement of a section does notnecessitate removing additional sections.

Also, the presence of gaps 702 enables a more forgiving manufacturingtolerance for gapped stator CFM system 700. For example, whenalternating magnets and flux conducting elements are repeatedly stackedtogether, manufacturing tolerance variations can be cumulative, leadingto magnets and/or flux conducting elements that are out of a desiredalignment. By utilizing one or more gaps 702, the location of magnetsand/or flux conducting elements can be periodically re-zeroed,eliminating tolerance stackup. As can be appreciated, less preciselymanufactured components may thus be effectively utilized, reducing theexpense of the system. Furthermore, the dimensions of gaps 702 may alsobe a function of at least one of an on-center distance between poles ingapped stator CFM system 700, a switch thickness of rotor 750, or thenumber of poles in gapped stator CFM system 700.

In addition to gapped stators disclosed above, principles of the presentdisclosure also contemplate “partial” or “truncated” stators. Inaccordance with an exemplary embodiment, a partial stator systemcomprises a stator that forms less than 360° coverage of a disk-shapedand/or annular rotor. In an exemplary embodiment, and with reference toFIG. 8A, a partial stator system 800 comprises a partial stator 810 anda rotor 850. Partial stator system 800 may be a portion of a fullycircumferential stator design. For example, partial stator 810 may becoupled to less than 25% of the circumference of rotor 850. In anotherembodiment, partial stator 810 is coupled to less than 50% of thecircumference of rotor 850. Moreover, partial stator 810 may at leastpartially enclose a portion of the circumference of rotor 850, forexample a portion in the range of 1%-95%. In various embodiments, therange may be from 1%-75%, 2%-66%, or 5%-33%. Furthermore, therelationship with partial stator 810 and rotor 850 may be described interms of relative arc lengths. For example, partial stator 810 may havean arc length less than 25% of the arc length of rotor 850.

In an exemplary embodiment and as illustrated in FIGS. 8B and 8C, apartial stator system 800 can also comprise gapped stator sections aspreviously described. In an exemplary embodiment, partial stator system800 is an axial gap configuration, as shown in FIG. 2A. In anotherexemplary embodiment, partial stator system 800 is a radial gapconfiguration, as shown in FIG. 2B.

In various exemplary embodiments, partial stator system 800 isconfigured with an engagement between stator 810 and rotor 850. Thisengagement can be utilized for different purposes. For example, theengagement can be tailored for different sized rotors and/or differentshaped rotors. Furthermore, in an exemplary embodiment the engagement isdesigned for at least one of: tailoring a voltage constant, tailoring atorque constant, tailoring a power density, or optimizing voltage and/ortorque density for a specific application, and/or the like. Moreover, ifpartial stator system 800 comprises multiple stator sections, anyparticular stator section may be individually adjusted, for example forone of reasons set forth above.

Moreover, multiple partial stator sections may desirably be utilized,for example, in order to product polyphase output and/or respond topolyphase input. In various exemplary embodiments, multiple partialstator sections may be utilized, each corresponding to a differentphase. However, any combination of partial stator sections and/or phasesmay be utilized, as desired.

In general, partial stator system 800 may be desirably utilized if anapplication requires less than the maximum power obtainable with a fullycircumferential stator. In an exemplary embodiment, a number ofcommutated flux stator sections in partial stator system 800 can becustomized to an application's requirements, for example a desired poweroutput, efficiency, expense, and/or the like. In an exemplaryembodiment, partial stator system 800 is designed based in part on aratio between desired electrical output and the mass of system 800.Partial stator system 800 may also be designed in part based on theratio between a rotor diameter and either of the electrical output orweight of system 800. In an exemplary embodiment, partial stator system800 achieves more torque without increasing the amount of the statormaterial by increasing the diameter of the rotor.

Such applications may include bikes, scooters, washing machines,motorcycles, portable generators, power tools, and/or small engineapplications. Partial stators may offer many and/or all of the benefitsof gapped stators as discussed above. Moreover, partial stator system800 may provide improved serviceability, for example because the statorcomponents are more accessible and/or easier to assemble/disassemblecompared to a fully circumferential stator.

Partial and/or gapped stators may be coupled to other components, forexample control electronics. In an exemplary embodiment and withreference to FIG. 9A, a partial stator system 900 further comprises anelectronics board 901 to capture the generated output from a coil 920.In another exemplary embodiment, electronics board 901 can be configuredto provide power to partial stator system 900, for example deliveringpower to drive a rotor. Furthermore, in an exemplary embodiment, partialstator system 900 may be implemented within a commutated flux machineand/or a transverse flux machine. In one exemplary embodiment, a partialstator 910 is electrically connected to a truncated coil 920 that ismounted directly to electronics board 901. Electronics board 901 may, inan exemplary embodiment, include various electronic components 930. Inan exemplary embodiment, electronic components 930 include integratedcircuits, capacitors, invertors, and other suitable components, asdesired.

Furthermore, in an exemplary embodiment, electronics board 901 islocated a short distance from partial stator 910, and thus the length oftruncated coil 920 from partial stator 910 to electronics board 901 isalso short. In an exemplary embodiment, the length of truncated coil 920from partial stator 910 to electronics board 901 is 1 inch or less. Inanother embodiment, the length of truncated coil 920 from partial stator910 to electronics board 901 is in the range of 1-2 inches. Moreover,the length of truncated coil 920 may be any suitable length; however,the length of truncated coil 920 may often be desirably minimized toreduce resistive and/or other losses.

In accordance with an exemplary embodiment, a thickness to length ratioof truncated coil 920 is configured to permit a significant percentageof heat generated in truncated coil 920 to be removed conductively. Inan exemplary embodiment, a significant percentage may be 70% or more ofthe generated heat. In various exemplary embodiments, a significantpercentage may be between about 40% of the generated heat and 95% of thegenerated heat. With the appropriate physical dimensions and/or materialproperties, in an exemplary embodiment, truncated coil 920 cansignificantly cool itself conductively. In an exemplary embodiment, theratio of the length of truncated coil 920 to the thickness of truncatedcoil 920 is about 20:1. In various exemplary embodiments, the ratio maybe between about 10:1 to about 75:1. Moreover, the ratio may be anysuitable ratio configured to allow truncated coil 920 to conductivelytransfer a suitable amount of heat, for example heat generated withinthe portion of truncated coil 920 at least partially enclosed bytruncated stator 910.

Moreover, additional components, for example cooling components 931, maybe coupled directly to coil 920. In an exemplary embodiment, coolingcomponents 931 may utilize at least one of radiant, convective, orconductive cooling. Cooling components 931 may also be formed fromand/or comprise a portion of coil 920. In this manner, thermal energytransferred from coil 920 to electronics board 901 may be reduced.Moreover, a rotor coupled to partial stator system 900 generally coolsmore effectively than a rotor in a fully circumferential stator system.This is due at least in part to the rotor only conducting flux in aportion of the rotation, which results in less heating of the rotor,also provides time for the rotor to cool when not conducting flux.

Furthermore, in various exemplary embodiments, truncated coil 920 isconfigured with minimal end turn material and/or no end turn material.An end turn may be considered to be a portion of a coil that is notlinked by substantial flux. In other words, the portion of the coil thatis not coupled to a flux concentrator and/or magnets may be consideredto be an end turn. In general, end turns are undesirable because theyincur coil losses without doing useful work. For example, an end turn ofa traditional motor incurs large losses as current flows through an endturn coil portion. Coil losses may include resistive losses, eddycurrent losses, thermal losses, and/or other coil losses associated witha given coil mass and/or configuration. Furthermore, heating of the coildue to resistance is also reduced if using less coil material. In oneembodiment, truncated coil 920 comprises a monolithic material core.Moreover, truncated coil 920 may comprise any suitable material, forexample layered, laminated, and/or otherwise shaped and/or formedmaterial, as desired.

In various exemplary embodiments, multiple commutated flux statorsections each have a corresponding truncated coil 920 in a singlewinding configuration, which can be connected to a single electronicsboard 901 (see, e.g., FIG. 9C). In other exemplary embodiments,truncated coil 920 comprises a double winding and/or more windings (see,e.g., FIG. 9B).

In addition to partial and/or gapped stators, principles of the presentdisclosure contemplate “floating” stators. As used herein, a “floating”stator may be a stator configured to be at least partially adjustableand/or moveable with respect to a rotor, for example in order tomaintain a desired air gap. With reference now to FIGS. 10A and 10B, inan exemplary embodiment a floating stator system 1000 comprises apartial stator 1010, a rotor 1050, and one or more guide mechanisms1011. Rotor 1050 may be attached to another object and held in place,and stator 1010 may be capable of floating. Alternatively, stator 1010may be attached to another object and held in place, and rotor 1050 maybe capable of floating.

In an exemplary embodiment, guide mechanisms 1011 are configured to helpalign rotor 1050 and/or mechanically facilitate a size of an air gapbetween rotor 1050 and partial stator 1010. Prior systems were oftenunable to achieve a targeted air gap as the diameter of the rotorincreased. For example, many motors and/or generators are configuredwith an air gap no smaller than 1/250 of the diameter of the rotor, inorder to prevent the rotor and stator from contacting and/or damagingone another. This is generally due to manufacturing tolerances and/orother difficulties, for example the difficulty of producing perfectlyround components.

In contrast, via use of a floating stator 1010, floating stator system1000 can be configured with an air gap independent of the diameter of arotor. For example, in an exemplary embodiment, floating stator system1000 is configured with a rotor diameter of 36 inches. This floatingstator system 1000 may also be configured with an air gap of only 0.036inches. In contrast, prior motors and/or generators having a similarrotor diameter were often configured with an air gap no smaller than0.144 inches (i.e., an air gap no small than 1/250 of the diameter ofthe rotor). By decoupling selecting an air gap from a correspondingrotor diameter, commutated and/or transverse flux systems having largerotor diameters (and corresponding high torque) may be configured withnarrow air gaps, improving the performance of the system. Stated anotherway, floating stator 1010 is capable of adjusting to gradual deviationsin the diameter of the rotor.

Guide mechanisms 1011 may be at least one of wheels, rails, bearings,bumpers, spacers, lubricious material, and/or the like. Moreover, guidemechanisms may be any suitable device configured to direct, guide,and/or align rotor 1050 and partial stator 1010. In various exemplaryembodiments, guide mechanisms 1011 also function to help clean offdebris from rotor 1050. In these embodiments, guide mechanisms 1011further comprise at least one of brushes, air or gas jets, wipers, ormagnetic pick-up wipers to deflect magnetic debris. Moreover, guidemechanisms 1011 may comprise any suitable mechanism for clearing debrisfrom rotor 1050.

Floating rotors can improve device manufacturing tolerances, ease ofmanufacturing, and robustness of overall design. Moreover, in anexemplary embodiment, a floating rotor further comprises a hublessdesign, such that the rotor is not connected to a central hub. In thismanner, increased space in the middle of the rotor is provided.Moreover, such a hubless design can increase heat dissipationcapabilities, for example by providing additional room for coolingairflow.

Furthermore, a hubless design may be configured to increase the floatingcapabilities of the rotor and/or stator, and/or to allow more tolerancewithin the system. Such increased floating and/or tolerance may beuseful in flux machines that undergo sudden changes of direction, forexample when installed in a vehicle. For example, in a vehicle, turningmay increase a chance of a rotor and stator scraping, due to the angularmomentum of the system. Moreover, in a vehicle, a rotor and stator mayscrape and/or otherwise contact one another in an undesirable manner forvarious reasons, for example contact with a pothole, lateralacceleration during a turn, an external force, and/or the like. Ahubless design may be configured to prevent rotor/stator contactresulting from any and/or all of the foregoing.

Suitable methods of forming and/or materials for stators, rotors, coils,switches, flux concentrators, and/or other flux conducting components oftransverse and/or commutated flux machines may be found in co-pendingU.S. Patent Application Ser. No. 12/611,733 filed Nov. 3, 2009, now U.S.Patent Application Publication No. 2010/0109452, entitled “TRANSVERSEAND/OR COMMUTATED FLUX SYSTEM ROTOR CONCEPTS”. Principles of the presentdisclosure may suitably be combined therewith.

Principles of the present disclosure may also suitably be combined withprinciples for rotors in transverse flux machines and/or commutated fluxmachines as disclosed in co-pending U.S. patent application Ser. No.12/611,733 filed Nov. 3, 2009, now U.S. Patent Application PublicationNo. 2010/0109452, entitled “TRANSVERSE AND/OR COMMUTATED FLUX SYSTEMROTOR CONCEPTS”, the contents of which are hereby incorporated byreference in their entirety.

Principles of the present disclosure may also suitably be combined withprinciples of polyphase transverse flux machines and/or polyphasecommutated flux machines as disclosed in co-pending U.S. PatentApplication Ser. No. 12/611,737 filed Nov. 3, 2009, now U.S. PatentApplication Publication No. 2010/0109453, entitled “POLYPHASE TRANSVERSEAND/OR COMMUTATED FLUX SYSTEMS”, the contents of which are herebyincorporated by reference in their entirety.

Moreover, principles of the present disclosure may suitably be combinedwith any number of principles disclosed in any one of and/or all of theU.S. Patent Applications incorporated by reference herein. Thus, forexample, a particular commutated flux machine may incorporate use of apartial stator, use of a tape wound rotor, use of a polyphase design,and/or the like. All such combinations, permutations, and/or otherinterrelationships are considered to be within the scope of the presentdisclosure.

While the principles of this disclosure have been shown in variousembodiments, many modifications of structure, arrangements, proportions,the elements, materials and components, used in practice, which areparticularly adapted for a specific environment and operatingrequirements may be used without departing from the principles and scopeof this disclosure. These and other changes or modifications areintended to be included within the scope of the present disclosure andmay be expressed in the following claims.

In the foregoing specification, the invention has been described withreference to various embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the present disclosure. Accordingly,the specification is to be regarded in an illustrative rather than arestrictive sense, and all such modifications are intended to beincluded within the scope of the present disclosure. Likewise, benefits,other advantages, and solutions to problems have been described abovewith regard to various embodiments. However, benefits, advantages,solutions to problems, and any element(s) that may cause any benefit,advantage, or solution to occur or become more pronounced are not to beconstrued as a critical, required, or essential feature or element ofany or all the claims. As used herein, the terms “comprises,”“comprising,” or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus. Also, as used herein,the terms “coupled,” “coupling,” or any other variation thereof, areintended to cover a physical connection, an electrical connection, amagnetic connection, an optical connection, a communicative connection,a functional connection, and/or any other connection. When languagesimilar to “at least one of A, B, or C” is used in the claims, thephrase is intended to mean any of the following: (1) at least one of A;(2) at least one of B; (3) at least one of C; (4) at least one of A andat least one of B; (5) at least one of B and at least one of C; (6) atleast one of A and at least one of C; or (7) at least one of A, at leastone of B, and at least one of C.

STATEMENT OF INVENTION

A commutated flux stator section, comprising a flux concentrator, afirst magnet connected to a first side of the flux concentrator andhaving an outer edge parallel to, and opposite of, the interface betweenthe first magnet and the flux concentrator, and a second magnetconnected to a second side of the flux concentrator opposite the firstside. The second magnet may have an outer edge parallel to, and oppositeof, the interface between the second magnet and the flux concentrator.The first magnet and the second magnet may be magnetically oriented suchthat a common magnetic pole is present on the first and second sides ofthe flux concentrator. The commutated flux stator section may partiallyenclose a radial section of a coil. The distance between the outer edgesof the first and second magnet may be substantially equal throughout thecommutated flux stator section partially enclosing the coil. The outeredge of the first magnet may be parallel to the outer edge of the secondmagnet. The first magnet and the second magnet may have the samethickness. The commutated flux stator section may comprise part of acommutated flux machine having an axis of rotation, and the commutatedflux stator section may be tapered towards the axis of rotation. Thefirst magnet, the second magnet, and the flux concentrator may beindividually tapered towards the axis of rotation.

A commutated flux stator section comprising a plurality of commutatedflux stator sections assembled at least partially about thecircumference of a rotor, wherein the arc length of the plurality ofcommutated flux stator sections is less than the circumference of therotor. A gap may be located between each of the plurality of commutatedflux stator sections. A supporting structure may be located between oneor more of the plurality of commutated flux stator sections. Atolerancing space may be located between at least two of the pluralityof commutated flux stator sections. The tolerancing space may beconfigured to facilitate assembly of a commutated flux machine. Thewidth of the tolerancing space may be a function of at least one of: amanufacturing tolerance, an on-center distance between poles in thecommutated flux machine, a switch thickness of the rotor, or the numberof poles in the commutated flux machine. The total arc length of theplurality of commutated flux stator sections may be in the range ofabout 1% to about 95% of the circumference of the rotor. A first subsetof the plurality of commutated flux stator sections may each comprise aflux concentrator having a first polarity. A remaining subset of theplurality of commutated flux stator sections may each comprise a fluxconcentrator having a second polarity opposite the first polarity. Therotor may be a multipath rotor.

1. An electrical machine, comprising: a rotor; a partial stator assemblycomprising: a flux concentrator; a first magnet connected to a firstside of the flux concentrator; a second magnet connected to a secondside of the flux concentrator opposite the first side, wherein the firstmagnet and the second magnet are magnetically oriented such that acommon magnetic pole is present on the first and second sides of theflux concentrator; and a guide mechanism configured to achieve aspecified air gap between the rotor and the partial stator assembly,wherein the electrical machine is at least one of a transverse fluxmachine or a commutated flux machine.
 2. The electrical machine of claim1, wherein the rotor is a hubless rotor.
 3. The electrical machine ofclaim 1, wherein the guide mechanism comprises multiple guiding wheels.4. The electrical machine of claim 1, wherein the air gap varies onlocal deviation of the rotor from round but does not vary based onoverall rotor out of roundness.
 5. The electrical machine of claim 1,wherein the specified air gap between the partial stator assembly andthe rotor is independent of the diameter of the rotor.
 6. The electricalmachine of claim 1, wherein the specified air gap is less than 1/250 ofthe diameter of the rotor.
 7. The electrical machine of claim 1, whereinthe rotor diameter is greater than 12 inches and the air gap is lessthan 0.05 inches.
 8. The electrical machine of claim 1, furthercomprising a debris collecting mechanism configured to remove debrisfrom the rotor as the rotor passes by the partial stator assembly. 9.The electrical machine of claim 1, wherein the guide mechanism isconfigured to move within a bounded range to reduce air gap variabilityresulting from non-uniformity of the rotor.
 10. The electrical machineof claim 9, wherein the non-uniformity of the rotor is the rotor beingout of round.
 11. The electrical machine of claim 1, wherein the guidemechanism is configured to prevent physical contact between the partialstator assembly and the rotor in the air gap region responsive anexternal force applied to the electrical machine.
 12. The electricalmachine of claim 1, wherein the rotor is a multipath rotor.
 13. Theelectrical machine of claim 1, further comprising a plurality of partialstator assemblies.
 14. The electrical machine of claim 13, wherein atleast two of the plurality of partial stator assemblies differ in phase.15. A method of configuring an electrical machine, the methodcomprising: coupling a truncated stator to a rotor via a guidemechanism, the rotor having a diameter; and configuring the guidemechanism to achieve a desired air gap between the truncated stator andthe rotor, wherein the desired air gap is independent of the diameter ofthe rotor, and wherein the electrical machine is at least one of atransverse flux machine or a commutated flux machine.
 16. The method ofclaim 15, further comprising: selecting a total mass of the truncatedstator; and calculating a diameter of the rotor to achieve a desiredtorque generated by the electrical machine.
 17. The method of claim 15,wherein the desired air gap is independent of an overall out ofroundness of the rotor.
 18. The method of claim 15, wherein the desiredair gap is less than 1/250 of the diameter of the rotor.
 19. The methodof claim 15, wherein the guide mechanism is configured to preventphysical contact between the truncated stator and the rotor in the airgap region responsive an external force applied to the electricalmachine.